// jQuery List DragSort v0.5.1
// Website: http://dragsort.codeplex.com/
// License: http://dragsort.codeplex.com/license
define(function (require, exports, module) {
	var jQuery = require("jquery");
	var userAgent = navigator.userAgent.toLowerCase();
	// Figure out what browser is being used
	jQuery.browser = {
		version: (userAgent.match( /.+(?:rv|it|ra|ie)[\/: ]([\d.]+)/ ) || [])[1],
		safari: /webkit/.test( userAgent ),
		opera: /opera/.test( userAgent ),
		msie: /msie/.test( userAgent ) && !/opera/.test( userAgent ),
		mozilla: /mozilla/.test( userAgent ) && !/(compatible|webkit)/.test( userAgent )
	};
	(function ($) {

		$.fn.dragsort = function (options) {
			if (options == "destroy") {
				$(this.selector).trigger("dragsort-uninit");
				return;
			}

			var opts = $.extend({}, $.fn.dragsort.defaults, options);
			var lists = [];
			var list = null, lastPos = null;

			this.each(function (i, cont) {

				//if list container is table, the browser automatically wraps rows in tbody if not specified so change list container to tbody so that children returns rows as user expected
				if ($(cont).is("table") && $(cont).children().size() == 1 && $(cont).children().is("tbody"))
					cont = $(cont).children().get(0);

				var newList = {
					draggedItem: null,
					placeHolderItem: null,
					pos: null,
					offset: null,
					offsetLimit: null,
					scroll: null,
					container: cont,

					init: function () {
						//set options to default values if not set
						var tagName = $(this.container).children().size() == 0 ? "li" : $(this.container).children(":first").get(0).tagName.toLowerCase();
						if (opts.itemSelector == "")
							opts.itemSelector = tagName;
						if (opts.dragSelector == "")
							opts.dragSelector = tagName;
						if (opts.placeHolderTemplate == "")
							opts.placeHolderTemplate = "<" + tagName + ">&nbsp;</" + tagName + ">";

						//listidx allows reference back to correct list variable instance
						$(this.container).attr("data-listidx", i).mousedown(this.grabItem).bind("dragsort-uninit", this.uninit);
						this.styleDragHandlers(true);
					},

					uninit: function () {
						var list = lists[$(this).attr("data-listidx")];
						$(list.container).unbind("mousedown", list.grabItem).unbind("dragsort-uninit");
						list.styleDragHandlers(false);
					},

					getItems: function () {
						return $(this.container).children(opts.itemSelector);
					},

					styleDragHandlers: function (cursor) {
						this.getItems().map(function () {
							return $(this).is(opts.dragSelector) ? this : $(this).find(opts.dragSelector).get();
						}).css("cursor", cursor ? "pointer" : "");
					},

					grabItem: function (e) {
						//if not left click or if clicked on excluded element (e.g. text box) or not a moveable list item return
						if (e.which != 1 || $(e.target).is(opts.dragSelectorExclude) || $(e.target).closest(opts.dragSelectorExclude).size() > 0 || $(e.target).closest(opts.itemSelector).size() == 0)
							return;

						//prevents selection, stops issue on Fx where dragging hyperlink doesn't work and on IE where it triggers mousemove even though mouse hasn't moved,
						//does also stop being able to click text boxes hence dragging on text boxes by default is disabled in dragSelectorExclude
						e.preventDefault();

						//change cursor to move while dragging
						var dragHandle = e.target;
						while (!$(dragHandle).is(opts.dragSelector)) {
							if (dragHandle == this) return;
							dragHandle = dragHandle.parentNode;
						}
						$(dragHandle).attr("data-cursor", $(dragHandle).css("cursor"));
						$(dragHandle).css("cursor", "move");

						//on mousedown wait for movement of mouse before triggering dragsort script (dragStart) to allow clicking of hyperlinks to work
						var list = lists[$(this).attr("data-listidx")];
						var item = this;
						var trigger = function () {
							list.dragStart.call(item, e);
							$(list.container).unbind("mousemove", trigger);
						};
						$(list.container).mousemove(trigger).mouseup(function () {
							$(list.container).unbind("mousemove", trigger);
							$(dragHandle).css("cursor", $(dragHandle).attr("data-cursor"));
						});
					},

					dragStart: function (e) {
						if (list != null && list.draggedItem != null)
							list.dropItem();

						list = lists[$(this).attr("data-listidx")];
						list.draggedItem = $(e.target).closest(opts.itemSelector);

						//record current position so on dragend we know if the dragged item changed position or not
						list.draggedItem.attr("data-origpos", $(this).attr("data-listidx") + "-" + list.getItems().index(list.draggedItem));

						//calculate mouse offset relative to draggedItem
						var mt = parseInt(list.draggedItem.css("marginTop"));
						var ml = parseInt(list.draggedItem.css("marginLeft"));
						list.offset = list.draggedItem.offset();
						list.offset.top = e.pageY - list.offset.top + (isNaN(mt) ? 0 : mt) - 1;
						list.offset.left = e.pageX - list.offset.left + (isNaN(ml) ? 0 : ml) - 1;

						//calculate box the dragged item can't be dragged outside of
						if (!opts.dragBetween) {
							var containerHeight = $(list.container).outerHeight() == 0 ? Math.max(1, Math.round(0.5 + list.getItems().size() * list.draggedItem.outerWidth() / $(list.container).outerWidth())) * list.draggedItem.outerHeight() : $(list.container).outerHeight();
							list.offsetLimit = $(list.container).offset();
							list.offsetLimit.right = list.offsetLimit.left + $(list.container).outerWidth() - list.draggedItem.outerWidth();
							list.offsetLimit.bottom = list.offsetLimit.top + containerHeight - list.draggedItem.outerHeight();
						}

						//create placeholder item
						var h = list.draggedItem.height();
						var w = list.draggedItem.width();
						if (opts.itemSelector == "tr") {
							list.draggedItem.children().each(function () {
								$(this).width($(this).width());
							});
							list.placeHolderItem = list.draggedItem.clone().attr("data-placeholder", true);
							list.draggedItem.after(list.placeHolderItem);
							list.placeHolderItem.children().each(function () {
								$(this).css({
									borderWidth: 0,
									width: $(this).width() + 1,
									height: $(this).height() + 1
								}).html("&nbsp;");
							});
						} else {
							list.draggedItem.after(opts.placeHolderTemplate);
							list.placeHolderItem = list.draggedItem.next().css({
								height: h,
								width: w
							}).attr("data-placeholder", true);
						}

						if (opts.itemSelector == "td") {
							var listTable = list.draggedItem.closest("table").get(0);
							$("<table id='" + listTable.id + "' style='border-width: 0px;' class='dragSortItem " + listTable.className + "'><tr></tr></table>").appendTo("body").children().append(list.draggedItem);
						}

						//style draggedItem while dragging
						var orig = list.draggedItem.attr("style");
						list.draggedItem.attr("data-origstyle", orig ? orig : "");
						list.draggedItem.css({position: "absolute", opacity: 0.8, "z-index": 999, height: h, width: w});

						//auto-scroll setup
						list.scroll = {
							moveX: 0,
							moveY: 0,
							maxX: $(document).width() - $(window).width(),
							maxY: $(document).height() - $(window).height()
						};
						list.scroll.scrollY = window.setInterval(function () {
							if (opts.scrollContainer != window) {
								$(opts.scrollContainer).scrollTop($(opts.scrollContainer).scrollTop() + list.scroll.moveY);
								return;
							}
							var t = $(opts.scrollContainer).scrollTop();
							if (list.scroll.moveY > 0 && t < list.scroll.maxY || list.scroll.moveY < 0 && t > 0) {
								$(opts.scrollContainer).scrollTop(t + list.scroll.moveY);
								list.draggedItem.css("top", list.draggedItem.offset().top + list.scroll.moveY + 1);
							}
						}, 10);
						list.scroll.scrollX = window.setInterval(function () {
							if (opts.scrollContainer != window) {
								$(opts.scrollContainer).scrollLeft($(opts.scrollContainer).scrollLeft() + list.scroll.moveX);
								return;
							}
							var l = $(opts.scrollContainer).scrollLeft();
							if (list.scroll.moveX > 0 && l < list.scroll.maxX || list.scroll.moveX < 0 && l > 0) {
								$(opts.scrollContainer).scrollLeft(l + list.scroll.moveX);
								list.draggedItem.css("left", list.draggedItem.offset().left + list.scroll.moveX + 1);
							}
						}, 10);

						//misc
						$(lists).each(function (i, l) {
							l.createDropTargets();
							l.buildPositionTable();
						});
						list.setPos(e.pageX, e.pageY);
						$(document).bind("mousemove", list.swapItems);
						$(document).bind("mouseup", list.dropItem);
						if (opts.scrollContainer != window)
							$(window).bind("DOMMouseScroll mousewheel", list.wheel);
					},

					//set position of draggedItem
					setPos: function (x, y) {
						//remove mouse offset so mouse cursor remains in same place on draggedItem instead of top left corner
						var top = y - this.offset.top;
						var left = x - this.offset.left;

						//limit top, left to within box draggedItem can't be dragged outside of
						if (!opts.dragBetween) {
							top = Math.min(this.offsetLimit.bottom, Math.max(top, this.offsetLimit.top));
							left = Math.min(this.offsetLimit.right, Math.max(left, this.offsetLimit.left));
						}

						//adjust top, left calculations to parent element instead of window if it's relative or absolute
						this.draggedItem.parents().each(function () {
							if ($(this).css("position") != "static" && (!$.browser.mozilla || $(this).css("display") != "table")) {
								var offset = $(this).offset();
								top -= offset.top;
								left -= offset.left;
								return false;
							}
						});

						//set x or y auto-scroll amount
						if (opts.scrollContainer == window) {
							y -= $(window).scrollTop();
							x -= $(window).scrollLeft();
							y = Math.max(0, y - $(window).height() + 5) + Math.min(0, y - 5);
							x = Math.max(0, x - $(window).width() + 5) + Math.min(0, x - 5);
						} else {
							var cont = $(opts.scrollContainer);
							var offset = cont.offset();
							y = Math.max(0, y - cont.height() - offset.top) + Math.min(0, y - offset.top);
							x = Math.max(0, x - cont.width() - offset.left) + Math.min(0, x - offset.left);
						}

						list.scroll.moveX = x == 0 ? 0 : x * opts.scrollSpeed / Math.abs(x);
						list.scroll.moveY = y == 0 ? 0 : y * opts.scrollSpeed / Math.abs(y);

						//move draggedItem to new mouse cursor location
						this.draggedItem.css({top: top, left: left});
					},

					//if scroll container is a div allow mouse wheel to scroll div instead of window when mouse is hovering over
					wheel: function (e) {
						if (($.browser.safari || $.browser.mozilla) && list && opts.scrollContainer != window) {
							var cont = $(opts.scrollContainer);
							var offset = cont.offset();
							if (e.pageX > offset.left && e.pageX < offset.left + cont.width() && e.pageY > offset.top && e.pageY < offset.top + cont.height()) {
								var delta = e.detail ? e.detail * 5 : e.wheelDelta / -2;
								cont.scrollTop(cont.scrollTop() + delta);
								e.preventDefault();
							}
						}
					},

					//build a table recording all the positions of the moveable list items
					buildPositionTable: function () {
						var pos = [];
						this.getItems().not([list.draggedItem[0], list.placeHolderItem[0]]).each(function (i) {
							var loc = $(this).offset();
							loc.right = loc.left + $(this).outerWidth();
							loc.bottom = loc.top + $(this).outerHeight();
							loc.elm = this;
							pos[i] = loc;
						});
						this.pos = pos;
					},

					dropItem: function () {
						if (list.draggedItem == null)
							return;

						//list.draggedItem.attr("style", "") doesn't work on IE8 and jQuery 1.5 or lower
						//list.draggedItem.removeAttr("style") doesn't work on chrome and jQuery 1.6 (works jQuery 1.5 or lower)
						var orig = list.draggedItem.attr("data-origstyle");
						list.draggedItem.attr("style", orig);
						if (orig == "")
							list.draggedItem.removeAttr("style");
						list.draggedItem.removeAttr("data-origstyle");

						list.styleDragHandlers(true);

						list.placeHolderItem.before(list.draggedItem);
						list.placeHolderItem.remove();

						$("[data-droptarget], .dragSortItem").remove();

						window.clearInterval(list.scroll.scrollY);
						window.clearInterval(list.scroll.scrollX);

						//if position changed call dragEnd
						if (list.draggedItem.attr("data-origpos") != $(lists).index(list) + "-" + list.getItems().index(list.draggedItem))
							opts.dragEnd.apply(list.draggedItem);
						list.draggedItem.removeAttr("data-origpos");

						list.draggedItem = null;
						$(document).unbind("mousemove", list.swapItems);
						$(document).unbind("mouseup", list.dropItem);
						if (opts.scrollContainer != window)
							$(window).unbind("DOMMouseScroll mousewheel", list.wheel);
						return false;
					},

					//swap the draggedItem (represented visually by placeholder) with the list item the it has been dragged on top of
					swapItems: function (e) {
						if (list.draggedItem == null)
							return false;

						//move draggedItem to mouse location
						list.setPos(e.pageX, e.pageY);

						//retrieve list and item position mouse cursor is over
						var ei = list.findPos(e.pageX, e.pageY);
						var nlist = list;
						for (var i = 0; ei == -1 && opts.dragBetween && i < lists.length; i++) {
							ei = lists[i].findPos(e.pageX, e.pageY);
							nlist = lists[i];
						}

						//if not over another moveable list item return
						if (ei == -1)
							return false;

						//save fixed items locations
						var children = function () {
							return $(nlist.container).children().not(nlist.draggedItem);
						};
						var fixed = children().not(opts.itemSelector).each(function (i) {
							this.idx = children().index(this);
						});

						//if moving draggedItem up or left place placeHolder before list item the dragged item is hovering over otherwise place it after
						if (lastPos == null || lastPos.top > list.draggedItem.offset().top || lastPos.left > list.draggedItem.offset().left)
							$(nlist.pos[ei].elm).before(list.placeHolderItem);
						else
							$(nlist.pos[ei].elm).after(list.placeHolderItem);

						//restore fixed items location
						fixed.each(function () {
							var elm = children().eq(this.idx).get(0);
							if (this != elm && children().index(this) < this.idx)
								$(this).insertAfter(elm);
							else if (this != elm)
								$(this).insertBefore(elm);
						});

						//misc
						$(lists).each(function (i, l) {
							l.createDropTargets();
							l.buildPositionTable();
						});
						lastPos = list.draggedItem.offset();
						return false;
					},

					//returns the index of the list item the mouse is over
					findPos: function (x, y) {
						for (var i = 0; i < this.pos.length; i++) {
							if (this.pos[i].left < x && this.pos[i].right > x && this.pos[i].top < y && this.pos[i].bottom > y)
								return i;
						}
						return -1;
					},

					//create drop targets which are placeholders at the end of other lists to allow dragging straight to the last position
					createDropTargets: function () {
						if (!opts.dragBetween)
							return;

						$(lists).each(function () {
							var ph = $(this.container).find("[data-placeholder]");
							var dt = $(this.container).find("[data-droptarget]");
							if (ph.size() > 0 && dt.size() > 0)
								dt.remove();
							else if (ph.size() == 0 && dt.size() == 0) {
								if (opts.itemSelector == "td")
									$(opts.placeHolderTemplate).attr("data-droptarget", true).appendTo(this.container);
								else
								//list.placeHolderItem.clone().removeAttr("data-placeholder") crashes in IE7 and jquery 1.5.1 (doesn't in jquery 1.4.2 or IE8)
									$(this.container).append(list.placeHolderItem.removeAttr("data-placeholder").clone().attr("data-droptarget", true));

								list.placeHolderItem.attr("data-placeholder", true);
							}
						});
					}
				};

				newList.init();
				lists.push(newList);
			});

			return this;
		};

		$.fn.dragsort.defaults = {
			itemSelector: "",
			dragSelector: "",
			dragSelectorExclude: "input, textarea",
			dragEnd: function () {
			},
			dragBetween: false,
			placeHolderTemplate: "",
			scrollContainer: window,
			scrollSpeed: 5
		};

	})(jQuery);
})